Electric motors or rotating electrical machines such as generators are provided in drive devices of hybrid vehicles or electric vehicles. This type of rotating electrical machine needs a large amount of current or is used in close proximity of an engine, and thus is disadvantage in a rise in temperature. For this reason, it is important to ensure safety by monitoring a coil temperature, a temperature of a lubricating oil for cooling, and the like by a temperature sensor at the same time and performing appropriate control by operating a safety circuit if a rise in temperature occurs.
For example, JP-A-2009-100538 describes a techniques where a thermistor 50 which is a temperature sensor is inserted into a temperature-sensing-element insertion hole 17 formed at a mold portion 20 formed by molding a parallel winding coil 11 and an inclined winding coil 12 disposed at a stator core 13. In this case, the temperature-sensing-element insertion hole 17 is disposed in the vicinity of the wound coils of the parallel winding coil 11 and the inclined winding coil 12 and a temperature of each of the coils 11 and 12 is monitored.
However, in JP-A-2009-100538, although a method of measuring the temperature of each of the coils 11 and 12 is disclosed, measuring of a temperature of a cooling oil is not disclosed. Therefore, one can conceive of separately providing a temperature sensor for measuring a temperature of an oil. In this case, the temperature sensor is attached to a member other than the stator core 3, and thus a new member for attaching the temperature sensor is required. Therefore, the cost may increase.
A need thus exists for an electric motor and a vehicle drive device using the electric motor which are not susceptible the drawback mentioned above.